I have itunes but only so my wife can put music on her ipad. Otherwise I never use it. I'm old fashioned and use media player. Maybe there are some codecs on this that have allowed movie maker to work for me.
Chaz, I think I know where you going wrong. You are using others copyrighted music so your videos can't be shown everywhere even though you state it's not owned by you and have a link to them, I mainly use music from this website. http://ccmixter.org/ It takes ages to find what I want. The attribution states whether it for commercial or non commercial use. On youtube its easier to get it accepted if it is okay for commercial use. I'm sure there are other websites that are better. So if you find any let me know.
See when I put my videos on my computer they automatically open with quick time player im really annoying some times as I can't do any decent editing